git/send-pack.c
Junio C Hamano 18c6653da0 Merge branch 'fs/ssh-signing'
Use ssh public crypto for object and push-cert signing.

* fs/ssh-signing:
  ssh signing: test that gpg fails for unknown keys
  ssh signing: tests for logs, tags & push certs
  ssh signing: duplicate t7510 tests for commits
  ssh signing: verify signatures using ssh-keygen
  ssh signing: provide a textual signing_key_id
  ssh signing: retrieve a default key from ssh-agent
  ssh signing: add ssh key format and signing code
  ssh signing: add test prereqs
  ssh signing: preliminary refactoring and clean-up
2021-10-25 16:06:58 -07:00

746 lines
19 KiB
C

#include "builtin.h"
#include "config.h"
#include "commit.h"
#include "refs.h"
#include "object-store.h"
#include "pkt-line.h"
#include "sideband.h"
#include "run-command.h"
#include "remote.h"
#include "connect.h"
#include "send-pack.h"
#include "quote.h"
#include "transport.h"
#include "version.h"
#include "oid-array.h"
#include "gpg-interface.h"
#include "cache.h"
#include "shallow.h"
int option_parse_push_signed(const struct option *opt,
const char *arg, int unset)
{
if (unset) {
*(int *)(opt->value) = SEND_PACK_PUSH_CERT_NEVER;
return 0;
}
switch (git_parse_maybe_bool(arg)) {
case 1:
*(int *)(opt->value) = SEND_PACK_PUSH_CERT_ALWAYS;
return 0;
case 0:
*(int *)(opt->value) = SEND_PACK_PUSH_CERT_NEVER;
return 0;
}
if (!strcasecmp("if-asked", arg)) {
*(int *)(opt->value) = SEND_PACK_PUSH_CERT_IF_ASKED;
return 0;
}
die("bad %s argument: %s", opt->long_name, arg);
}
static void feed_object(const struct object_id *oid, FILE *fh, int negative)
{
if (negative &&
!has_object_file_with_flags(oid,
OBJECT_INFO_SKIP_FETCH_OBJECT |
OBJECT_INFO_QUICK))
return;
if (negative)
putc('^', fh);
fputs(oid_to_hex(oid), fh);
putc('\n', fh);
}
/*
* Make a pack stream and spit it out into file descriptor fd
*/
static int pack_objects(int fd, struct ref *refs, struct oid_array *advertised,
struct oid_array *negotiated,
struct send_pack_args *args)
{
/*
* The child becomes pack-objects --revs; we feed
* the revision parameters to it via its stdin and
* let its stdout go back to the other end.
*/
struct child_process po = CHILD_PROCESS_INIT;
FILE *po_in;
int i;
int rc;
strvec_push(&po.args, "pack-objects");
strvec_push(&po.args, "--all-progress-implied");
strvec_push(&po.args, "--revs");
strvec_push(&po.args, "--stdout");
if (args->use_thin_pack)
strvec_push(&po.args, "--thin");
if (args->use_ofs_delta)
strvec_push(&po.args, "--delta-base-offset");
if (args->quiet || !args->progress)
strvec_push(&po.args, "-q");
if (args->progress)
strvec_push(&po.args, "--progress");
if (is_repository_shallow(the_repository))
strvec_push(&po.args, "--shallow");
po.in = -1;
po.out = args->stateless_rpc ? -1 : fd;
po.git_cmd = 1;
po.clean_on_exit = 1;
if (start_command(&po))
die_errno("git pack-objects failed");
/*
* We feed the pack-objects we just spawned with revision
* parameters by writing to the pipe.
*/
po_in = xfdopen(po.in, "w");
for (i = 0; i < advertised->nr; i++)
feed_object(&advertised->oid[i], po_in, 1);
for (i = 0; i < negotiated->nr; i++)
feed_object(&negotiated->oid[i], po_in, 1);
while (refs) {
if (!is_null_oid(&refs->old_oid))
feed_object(&refs->old_oid, po_in, 1);
if (!is_null_oid(&refs->new_oid))
feed_object(&refs->new_oid, po_in, 0);
refs = refs->next;
}
fflush(po_in);
if (ferror(po_in))
die_errno("error writing to pack-objects");
fclose(po_in);
if (args->stateless_rpc) {
char *buf = xmalloc(LARGE_PACKET_MAX);
while (1) {
ssize_t n = xread(po.out, buf, LARGE_PACKET_MAX);
if (n <= 0)
break;
send_sideband(fd, -1, buf, n, LARGE_PACKET_MAX);
}
free(buf);
close(po.out);
po.out = -1;
}
rc = finish_command(&po);
if (rc) {
/*
* For a normal non-zero exit, we assume pack-objects wrote
* something useful to stderr. For death by signal, though,
* we should mention it to the user. The exception is SIGPIPE
* (141), because that's a normal occurrence if the remote end
* hangs up (and we'll report that by trying to read the unpack
* status).
*/
if (rc > 128 && rc != 141)
error("pack-objects died of signal %d", rc - 128);
return -1;
}
return 0;
}
static int receive_unpack_status(struct packet_reader *reader)
{
if (packet_reader_read(reader) != PACKET_READ_NORMAL)
return error(_("unexpected flush packet while reading remote unpack status"));
if (!skip_prefix(reader->line, "unpack ", &reader->line))
return error(_("unable to parse remote unpack status: %s"), reader->line);
if (strcmp(reader->line, "ok"))
return error(_("remote unpack failed: %s"), reader->line);
return 0;
}
static int receive_status(struct packet_reader *reader, struct ref *refs)
{
struct ref *hint;
int ret;
struct ref_push_report *report = NULL;
int new_report = 0;
int once = 0;
hint = NULL;
ret = receive_unpack_status(reader);
while (1) {
struct object_id old_oid, new_oid;
const char *head;
const char *refname;
char *p;
if (packet_reader_read(reader) != PACKET_READ_NORMAL)
break;
head = reader->line;
p = strchr(head, ' ');
if (!p) {
error("invalid status line from remote: %s", reader->line);
ret = -1;
break;
}
*p++ = '\0';
if (!strcmp(head, "option")) {
const char *key, *val;
if (!hint || !(report || new_report)) {
if (!once++)
error("'option' without a matching 'ok/ng' directive");
ret = -1;
continue;
}
if (new_report) {
if (!hint->report) {
CALLOC_ARRAY(hint->report, 1);
report = hint->report;
} else {
report = hint->report;
while (report->next)
report = report->next;
CALLOC_ARRAY(report->next, 1);
report = report->next;
}
new_report = 0;
}
key = p;
p = strchr(key, ' ');
if (p)
*p++ = '\0';
val = p;
if (!strcmp(key, "refname"))
report->ref_name = xstrdup_or_null(val);
else if (!strcmp(key, "old-oid") && val &&
!parse_oid_hex(val, &old_oid, &val))
report->old_oid = oiddup(&old_oid);
else if (!strcmp(key, "new-oid") && val &&
!parse_oid_hex(val, &new_oid, &val))
report->new_oid = oiddup(&new_oid);
else if (!strcmp(key, "forced-update"))
report->forced_update = 1;
continue;
}
report = NULL;
new_report = 0;
if (strcmp(head, "ok") && strcmp(head, "ng")) {
error("invalid ref status from remote: %s", head);
ret = -1;
break;
}
refname = p;
p = strchr(refname, ' ');
if (p)
*p++ = '\0';
/* first try searching at our hint, falling back to all refs */
if (hint)
hint = find_ref_by_name(hint, refname);
if (!hint)
hint = find_ref_by_name(refs, refname);
if (!hint) {
warning("remote reported status on unknown ref: %s",
refname);
continue;
}
if (hint->status != REF_STATUS_EXPECTING_REPORT &&
hint->status != REF_STATUS_OK &&
hint->status != REF_STATUS_REMOTE_REJECT) {
warning("remote reported status on unexpected ref: %s",
refname);
continue;
}
if (!strcmp(head, "ng")) {
hint->status = REF_STATUS_REMOTE_REJECT;
if (p)
hint->remote_status = xstrdup(p);
else
hint->remote_status = "failed";
} else {
hint->status = REF_STATUS_OK;
hint->remote_status = xstrdup_or_null(p);
new_report = 1;
}
}
return ret;
}
static int sideband_demux(int in, int out, void *data)
{
int *fd = data, ret;
if (async_with_fork())
close(fd[1]);
ret = recv_sideband("send-pack", fd[0], out);
close(out);
return ret;
}
static int advertise_shallow_grafts_cb(const struct commit_graft *graft, void *cb)
{
struct strbuf *sb = cb;
if (graft->nr_parent == -1)
packet_buf_write(sb, "shallow %s\n", oid_to_hex(&graft->oid));
return 0;
}
static void advertise_shallow_grafts_buf(struct strbuf *sb)
{
if (!is_repository_shallow(the_repository))
return;
for_each_commit_graft(advertise_shallow_grafts_cb, sb);
}
#define CHECK_REF_NO_PUSH -1
#define CHECK_REF_STATUS_REJECTED -2
#define CHECK_REF_UPTODATE -3
static int check_to_send_update(const struct ref *ref, const struct send_pack_args *args)
{
if (!ref->peer_ref && !args->send_mirror)
return CHECK_REF_NO_PUSH;
/* Check for statuses set by set_ref_status_for_push() */
switch (ref->status) {
case REF_STATUS_REJECT_NONFASTFORWARD:
case REF_STATUS_REJECT_ALREADY_EXISTS:
case REF_STATUS_REJECT_FETCH_FIRST:
case REF_STATUS_REJECT_NEEDS_FORCE:
case REF_STATUS_REJECT_STALE:
case REF_STATUS_REJECT_REMOTE_UPDATED:
case REF_STATUS_REJECT_NODELETE:
return CHECK_REF_STATUS_REJECTED;
case REF_STATUS_UPTODATE:
return CHECK_REF_UPTODATE;
default:
case REF_STATUS_EXPECTING_REPORT:
/* already passed checks on the local side */
case REF_STATUS_OK:
/* of course this is OK */
return 0;
}
}
/*
* the beginning of the next line, or the end of buffer.
*
* NEEDSWORK: perhaps move this to git-compat-util.h or somewhere and
* convert many similar uses found by "git grep -A4 memchr".
*/
static const char *next_line(const char *line, size_t len)
{
const char *nl = memchr(line, '\n', len);
if (!nl)
return line + len; /* incomplete line */
return nl + 1;
}
static int generate_push_cert(struct strbuf *req_buf,
const struct ref *remote_refs,
struct send_pack_args *args,
const char *cap_string,
const char *push_cert_nonce)
{
const struct ref *ref;
struct string_list_item *item;
char *signing_key_id = xstrdup(get_signing_key_id());
const char *cp, *np;
struct strbuf cert = STRBUF_INIT;
int update_seen = 0;
strbuf_addstr(&cert, "certificate version 0.1\n");
strbuf_addf(&cert, "pusher %s ", signing_key_id);
datestamp(&cert);
strbuf_addch(&cert, '\n');
if (args->url && *args->url) {
char *anon_url = transport_anonymize_url(args->url);
strbuf_addf(&cert, "pushee %s\n", anon_url);
free(anon_url);
}
if (push_cert_nonce[0])
strbuf_addf(&cert, "nonce %s\n", push_cert_nonce);
if (args->push_options)
for_each_string_list_item(item, args->push_options)
strbuf_addf(&cert, "push-option %s\n", item->string);
strbuf_addstr(&cert, "\n");
for (ref = remote_refs; ref; ref = ref->next) {
if (check_to_send_update(ref, args) < 0)
continue;
update_seen = 1;
strbuf_addf(&cert, "%s %s %s\n",
oid_to_hex(&ref->old_oid),
oid_to_hex(&ref->new_oid),
ref->name);
}
if (!update_seen)
goto free_return;
if (sign_buffer(&cert, &cert, get_signing_key()))
die(_("failed to sign the push certificate"));
packet_buf_write(req_buf, "push-cert%c%s", 0, cap_string);
for (cp = cert.buf; cp < cert.buf + cert.len; cp = np) {
np = next_line(cp, cert.buf + cert.len - cp);
packet_buf_write(req_buf,
"%.*s", (int)(np - cp), cp);
}
packet_buf_write(req_buf, "push-cert-end\n");
free_return:
free(signing_key_id);
strbuf_release(&cert);
return update_seen;
}
#define NONCE_LEN_LIMIT 256
static void reject_invalid_nonce(const char *nonce, int len)
{
int i = 0;
if (NONCE_LEN_LIMIT <= len)
die("the receiving end asked to sign an invalid nonce <%.*s>",
len, nonce);
for (i = 0; i < len; i++) {
int ch = nonce[i] & 0xFF;
if (isalnum(ch) ||
ch == '-' || ch == '.' ||
ch == '/' || ch == '+' ||
ch == '=' || ch == '_')
continue;
die("the receiving end asked to sign an invalid nonce <%.*s>",
len, nonce);
}
}
static void get_commons_through_negotiation(const char *url,
const struct ref *remote_refs,
struct oid_array *commons)
{
struct child_process child = CHILD_PROCESS_INIT;
const struct ref *ref;
int len = the_hash_algo->hexsz + 1; /* hash + NL */
child.git_cmd = 1;
child.no_stdin = 1;
child.out = -1;
strvec_pushl(&child.args, "fetch", "--negotiate-only", NULL);
for (ref = remote_refs; ref; ref = ref->next) {
if (!is_null_oid(&ref->new_oid))
strvec_pushf(&child.args, "--negotiation-tip=%s", oid_to_hex(&ref->new_oid));
}
strvec_push(&child.args, url);
if (start_command(&child))
die(_("send-pack: unable to fork off fetch subprocess"));
do {
char hex_hash[GIT_MAX_HEXSZ + 1];
int read_len = read_in_full(child.out, hex_hash, len);
struct object_id oid;
const char *end;
if (!read_len)
break;
if (read_len != len)
die("invalid length read %d", read_len);
if (parse_oid_hex(hex_hash, &oid, &end) || *end != '\n')
die("invalid hash");
oid_array_append(commons, &oid);
} while (1);
if (finish_command(&child)) {
/*
* The information that push negotiation provides is useful but
* not mandatory.
*/
warning(_("push negotiation failed; proceeding anyway with push"));
}
}
int send_pack(struct send_pack_args *args,
int fd[], struct child_process *conn,
struct ref *remote_refs,
struct oid_array *extra_have)
{
struct oid_array commons = OID_ARRAY_INIT;
int in = fd[0];
int out = fd[1];
struct strbuf req_buf = STRBUF_INIT;
struct strbuf cap_buf = STRBUF_INIT;
struct ref *ref;
int need_pack_data = 0;
int allow_deleting_refs = 0;
int status_report = 0;
int use_sideband = 0;
int quiet_supported = 0;
int agent_supported = 0;
int advertise_sid = 0;
int push_negotiate = 0;
int use_atomic = 0;
int atomic_supported = 0;
int use_push_options = 0;
int push_options_supported = 0;
int object_format_supported = 0;
unsigned cmds_sent = 0;
int ret;
struct async demux;
const char *push_cert_nonce = NULL;
struct packet_reader reader;
if (!remote_refs) {
fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
"Perhaps you should specify a branch.\n");
return 0;
}
git_config_get_bool("push.negotiate", &push_negotiate);
if (push_negotiate)
get_commons_through_negotiation(args->url, remote_refs, &commons);
git_config_get_bool("transfer.advertisesid", &advertise_sid);
/* Does the other end support the reporting? */
if (server_supports("report-status-v2"))
status_report = 2;
else if (server_supports("report-status"))
status_report = 1;
if (server_supports("delete-refs"))
allow_deleting_refs = 1;
if (server_supports("ofs-delta"))
args->use_ofs_delta = 1;
if (server_supports("side-band-64k"))
use_sideband = 1;
if (server_supports("quiet"))
quiet_supported = 1;
if (server_supports("agent"))
agent_supported = 1;
if (!server_supports("session-id"))
advertise_sid = 0;
if (server_supports("no-thin"))
args->use_thin_pack = 0;
if (server_supports("atomic"))
atomic_supported = 1;
if (server_supports("push-options"))
push_options_supported = 1;
if (!server_supports_hash(the_hash_algo->name, &object_format_supported))
die(_("the receiving end does not support this repository's hash algorithm"));
if (args->push_cert != SEND_PACK_PUSH_CERT_NEVER) {
int len;
push_cert_nonce = server_feature_value("push-cert", &len);
if (push_cert_nonce) {
reject_invalid_nonce(push_cert_nonce, len);
push_cert_nonce = xmemdupz(push_cert_nonce, len);
} else if (args->push_cert == SEND_PACK_PUSH_CERT_ALWAYS) {
die(_("the receiving end does not support --signed push"));
} else if (args->push_cert == SEND_PACK_PUSH_CERT_IF_ASKED) {
warning(_("not sending a push certificate since the"
" receiving end does not support --signed"
" push"));
}
}
if (args->atomic && !atomic_supported)
die(_("the receiving end does not support --atomic push"));
use_atomic = atomic_supported && args->atomic;
if (args->push_options && !push_options_supported)
die(_("the receiving end does not support push options"));
use_push_options = push_options_supported && args->push_options;
if (status_report == 1)
strbuf_addstr(&cap_buf, " report-status");
else if (status_report == 2)
strbuf_addstr(&cap_buf, " report-status-v2");
if (use_sideband)
strbuf_addstr(&cap_buf, " side-band-64k");
if (quiet_supported && (args->quiet || !args->progress))
strbuf_addstr(&cap_buf, " quiet");
if (use_atomic)
strbuf_addstr(&cap_buf, " atomic");
if (use_push_options)
strbuf_addstr(&cap_buf, " push-options");
if (object_format_supported)
strbuf_addf(&cap_buf, " object-format=%s", the_hash_algo->name);
if (agent_supported)
strbuf_addf(&cap_buf, " agent=%s", git_user_agent_sanitized());
if (advertise_sid)
strbuf_addf(&cap_buf, " session-id=%s", trace2_session_id());
/*
* NEEDSWORK: why does delete-refs have to be so specific to
* send-pack machinery that set_ref_status_for_push() cannot
* set this bit for us???
*/
for (ref = remote_refs; ref; ref = ref->next)
if (ref->deletion && !allow_deleting_refs)
ref->status = REF_STATUS_REJECT_NODELETE;
/*
* Clear the status for each ref and see if we need to send
* the pack data.
*/
for (ref = remote_refs; ref; ref = ref->next) {
switch (check_to_send_update(ref, args)) {
case 0: /* no error */
break;
case CHECK_REF_STATUS_REJECTED:
/*
* When we know the server would reject a ref update if
* we were to send it and we're trying to send the refs
* atomically, abort the whole operation.
*/
if (use_atomic) {
strbuf_release(&req_buf);
strbuf_release(&cap_buf);
reject_atomic_push(remote_refs, args->send_mirror);
error("atomic push failed for ref %s. status: %d\n",
ref->name, ref->status);
return args->porcelain ? 0 : -1;
}
/* else fallthrough */
default:
continue;
}
if (!ref->deletion)
need_pack_data = 1;
if (args->dry_run || !status_report)
ref->status = REF_STATUS_OK;
else
ref->status = REF_STATUS_EXPECTING_REPORT;
}
if (!args->dry_run)
advertise_shallow_grafts_buf(&req_buf);
/*
* Finally, tell the other end!
*/
if (!args->dry_run && push_cert_nonce)
cmds_sent = generate_push_cert(&req_buf, remote_refs, args,
cap_buf.buf, push_cert_nonce);
else if (!args->dry_run)
for (ref = remote_refs; ref; ref = ref->next) {
char *old_hex, *new_hex;
if (check_to_send_update(ref, args) < 0)
continue;
old_hex = oid_to_hex(&ref->old_oid);
new_hex = oid_to_hex(&ref->new_oid);
if (!cmds_sent) {
packet_buf_write(&req_buf,
"%s %s %s%c%s",
old_hex, new_hex, ref->name, 0,
cap_buf.buf);
cmds_sent = 1;
} else {
packet_buf_write(&req_buf, "%s %s %s",
old_hex, new_hex, ref->name);
}
}
if (use_push_options) {
struct string_list_item *item;
packet_buf_flush(&req_buf);
for_each_string_list_item(item, args->push_options)
packet_buf_write(&req_buf, "%s", item->string);
}
if (args->stateless_rpc) {
if (!args->dry_run && (cmds_sent || is_repository_shallow(the_repository))) {
packet_buf_flush(&req_buf);
send_sideband(out, -1, req_buf.buf, req_buf.len, LARGE_PACKET_MAX);
}
} else {
write_or_die(out, req_buf.buf, req_buf.len);
packet_flush(out);
}
strbuf_release(&req_buf);
strbuf_release(&cap_buf);
if (use_sideband && cmds_sent) {
memset(&demux, 0, sizeof(demux));
demux.proc = sideband_demux;
demux.data = fd;
demux.out = -1;
demux.isolate_sigpipe = 1;
if (start_async(&demux))
die("send-pack: unable to fork off sideband demultiplexer");
in = demux.out;
}
packet_reader_init(&reader, in, NULL, 0,
PACKET_READ_CHOMP_NEWLINE |
PACKET_READ_DIE_ON_ERR_PACKET);
if (need_pack_data && cmds_sent) {
if (pack_objects(out, remote_refs, extra_have, &commons, args) < 0) {
if (args->stateless_rpc)
close(out);
if (git_connection_is_socket(conn))
shutdown(fd[0], SHUT_WR);
/*
* Do not even bother with the return value; we know we
* are failing, and just want the error() side effects,
* as well as marking refs with their remote status (if
* we get one).
*/
if (status_report)
receive_status(&reader, remote_refs);
if (use_sideband) {
close(demux.out);
finish_async(&demux);
}
fd[1] = -1;
return -1;
}
if (!args->stateless_rpc)
/* Closed by pack_objects() via start_command() */
fd[1] = -1;
}
if (args->stateless_rpc && cmds_sent)
packet_flush(out);
if (status_report && cmds_sent)
ret = receive_status(&reader, remote_refs);
else
ret = 0;
if (args->stateless_rpc)
packet_flush(out);
if (use_sideband && cmds_sent) {
close(demux.out);
if (finish_async(&demux)) {
error("error in sideband demultiplexer");
ret = -1;
}
}
if (ret < 0)
return ret;
if (args->porcelain)
return 0;
for (ref = remote_refs; ref; ref = ref->next) {
switch (ref->status) {
case REF_STATUS_NONE:
case REF_STATUS_UPTODATE:
case REF_STATUS_OK:
break;
default:
return -1;
}
}
return 0;
}